Cappoletti weir is a

A)
trapezoidal weir, whose sides slope 1 horizontal to 2 verticals
B)
triangular weir whose notch angle is 90°
C)
a combination of rectangular and triangular weirs
D)
rectangular weir whose length is kept 3 times the height of the water above sill

Correct Answer :   trapezoidal weir, whose sides slope 1 horizontal to 2 verticals